Delordosation devices are required for various purposes, for example in sit/stand exercise machines or wheel chairs when a verticalization function exists. This is a system that permits a user with restricted mobility to be transferred from a seated position to a standing position. Typical restricted mobility of users of such a sit/stand exercise machine or a wheel chair can originate from any conceivable forms of diseases or disabilities. These are, for example, spasticities, paraplegia, apallic syndrome, weakness or failure of the muscular system due to neurological diseases (MS; ALS; hemiplegia), as well as disability patterns with distinctive contractures which are due to a considerable shortening of the muscles and ligaments. With the aid of a sit/stand exercise machine, for example a therapeutic measure can be performed. To this end, sit/stand exercise machines, but also wheel chairs, that comprise a seating surface on which the user can sit and which can be additionally fixated by suited support aids are known. By swiveling the seating surface, it is achieved here that the user can be transferred to a standing position to at least partially remove the restricted mobility or to give therapy to the patients by therapeutic measures.
Verticalization devices are known in wheel chairs, for example from the European Patent EP 0 815 822 B1. This wheel chair permits to bring the wheel chair user into a nearly vertical position and to make him nearly adopt the posture of a standing person. Especially for wheel chair users with a restricted or non-restricted musculoskeletal system of the upper portion of the body, or for all persons who cannot stand, it is extremely helpful if the posture adopted by the verticalization device would correspond to a standing position of a person not restricted in his/her mobility. For this, it is necessary to support the function of the skeleton such that it can adopt its maximal support and standing function corresponding to its possibly restricted ability. Thus, a problem repeatedly occurs in that full-range hip extension, this means a hip extension corresponding to the anatomically possible degree of motion, can often not be achieved by the musculoskeletal system of the wheel chair user. This is in particular true in case of a spasticity of the hip flexor or a poor posture of the pelvis. Already with a hip flexor contracture caused by sitting permanently, a restricted hip mobility can be caused or with persons suffering from diplegia who have a restricted muscle function, full-range hip extension can be hindered and hyperlordosis can arise from this.
Sit/stand exercise machines are employed as therapeutic measures in clinics and therapy institutions to motivate the patients with restricted mobility to actively take part in life and avoid secondary diseases caused by sitting or lying for a relatively long time. The sit/stand exercise machines are essentially used to protect the patient from further damages to the vertebral column, while neurological patients can learn to stand alone again with the aid of the sit/stand exercise machine. For this, it is possible not to only learn the functions of standing again with the aid of a sit/stand exercise machine, but moreover to sufficiently utilize the freedom gained. Sit/stand exercise machines are therefore employed in the therapeutic field in hospitals, in the private field for self-therapy, or in the integrative field, and they usually not only serve for one patient, but can be time and again adapted to various patients of different heights if need be.
From the prior art, seating surfaces for wheel chairs and sit/stand exercise machines with swiveling mechanisms are known. However, in such an embodiment, the pelvis is only pushed forward. The pelvis tilted forward as a consequence causes a hyperlordosation (extreme S-shaped bending, also referred to as hollow back) of the vertebral column during the straightening up. A secondary disease of hyperlordosis is an extreme compression in the facet articulations of the lumbar spine resulting in backaches. In the long term, hypermobilities and instabilities can occur in these back articulations with possible nerve constrictions or incarcerations. The ultimate goal of verticalization must accordingly be a physiologically favorable spine support.